Automatic sprinkler



L. M. LEWIS AUTOMATIC SPRINKLER Sept. 6,

Filed Aug. 25, 1936 AOEY.

Patented Sept. 6, 1938 UNlTED STATES PATENT OFFICE 4 Claims.

This invention relates to automatic sprinklers such as are commonly employed for the purpose of releasing a stream of water for fire fighting purposes when a certain predetermined tempera- 5 ture has been reached at the point where the sprinkler is located.

At the present time there has come into fairly Widespread use an automatic sprinkler which comprises a yoke that carries at one end a threaded plug, which is designed to be screwed into the extremity of a pipe line constituting a source of water supply. This plug is provided with a closure which normally seals the pipe line against the escape of water. A strut assembly is associated with the closure and has pressure applied thereto by a threaded stem which is carried by the yoke.

This strut assembly includes a cylinder and piston, together with a disc which normally maintains the cylinder and piston in an extended relationship. This disc is of a metallic alloy, which is well-known in this art, and which is responsive to temperature changes, so that when a certain predetermined temperature has been arrived at the disc will melt or evaporate, permitting a relative collapse of the piston with respect to the cylinder under the influence of the pressure applied thereon by the threaded stem, and when the piston and cylinder collapse, the entire strut assembly falls away from retaining position and permits the closure to be blown off, under the influence of the water pressure in the pipe line.

The above described construction is typical of one type of automatic sprinkler which is meeting with a certain amount of approval with the buying public, but certain disadvantages attach to the present arrangement, and which, disadvantages are intended to be obviated by the present invention.

These automatic sprinklers are designed to become effective at certain predetermined temperatures, and the controlling element is the fusible disc. By properly controlling the ingredients of the alloy, these discs are made to fuse at certain predetermined temperatures. It is, therefore, of the utmost importance that each sprinkler as an entirety include a proper disc.

With the now known arrangement of assembling these sprinklers, the disc is hidden within the cylinder, and as a result the wrong disc is ofttimes assembled with a certain sprinkler. These sprinklers ordinarily include a marking at the temperature at which they are intended 55 to become effective, and with the wrong disc assembled therein, the sprinkler will either start the stream of water too soon, so as to cause water damage, or too late, to permit heavy damage by fire.

This invention, therefore, has in view as an important objective the provision of an automatic sprinkler of the character above noted, in which the fusible element is rendered visible, so that definite assurance may be had at any time that the proper disc is assembled with the particular sprinkler.

More particularly this invention has in view, as a further objective, the provision of an arrangement whereby each fusible disc will be identifiable as to the temperature at which it 15 will fuse. The invention has in View an arrangement whereby different colors will be employed for different temperatures.

In carrying out the present invention in its fundamental concept, the cylinder which houses the fusible disc is made from a transparent material, such as quartz, while the disc which is housed therein is made of an appropriate color which is easily noticeable, and identifies the temperature at which the disc will fuse. 25

An advantage associated with the use of a quartz cylinder of the character noted, is that such a cylinder is not susceptible of attack or destruction by corrosion, as are many of the materials which have heretofore been employed for this purpose. Yet another advantage is that the quartz cylinder permits of a substantially. instantaneous transmission of heat to the fusible disc within the cylinder, as very little heat is absorbed by the quartz itself. It is also notable that any friction between the piston and cylinder is materially reduced by the quartz cylinder.

Heretofore it has been the practice to so arrange the piston and cylinder that the piston is above the cylinder, whereby dirt and other foreign matter often enters in between the piston and cylinder and interferes with the effective operation thereof.

Accordingly, a further object of the present invention is to provide an automatic sprinkler of the character above described, in which the cylinder and piston are so disposed in the strut assembly that the cylinder is above the piston, thereby obviating the possibility of accumulating dirt and foreign matter between the piston and cylinder.

This invention contemplates an arrangement in which the relative positions of the cylinder and piston may be interchanged to insure of the cylinder being above the piston, regardless of how the sprinkler is installed.

Various other more detailed objects and advantages will in part become apparent, and in part be hereinafter stated, as the description of the invention proceeds.

The invention, therefore, comprises an automatic sprinkler of the character above noted, which includes a cylinder and piston assembly as a part of the strut mechanism, and which cylinder and piston assembly is arranged with the cylinder disposed above the piston, and with the cylinder made from some transparent material, such as quartz. prevents collapse of the cylinder and is completely housed with the quartz cylinder, is provided with appropriate indicia, such as a coloring for indicating the temperature at which it will fuse.

For a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawing wherein Figure 1 is a View in side elevation of an automatic sprinkler, made in accordance with the precepts of this invention,

Figure 2 is a sectional view of the several elements of the piston and cylinder assembly in distended relationship,

Figure 3 is a side view taken as a section through the cylinder and piston in their normal closure supporting position, and

Figure 4 is a view in side elevation of the cylinder and piston assembly.

Referring now to the drawing, wherein like ref erence characters denote corresponding parts, an

automatic sprinkler, such as is contemplated bythis invention, is shown as comprising a yoke I0 which carries at one end a plug II, which is threaded, as indicated at I2 and formed with a bore, indicated at I3. The plug I2 is intended to be threaded into the extremity of a pipe line which constitutes the supply of water under pressure.

A closure, indicated at I4, normally closes the end of the bore I3 and seals the same against the escape of water. This closure I4 comprises a thin metallic disc I5, which has a centrally depressed portion, as indicated at I6, and a backing member I! that is provided with a transverse groove, indicated at I8. This backing member I! is complementally shaped to the shape of the disc I5, and serves to positively hold the latter in position.

A strut assembly, which is referred to in its entirety by the reference character I9, engages against the closure I4, while at the upper extremity pressure is applied to the strut assembly I9 by a threaded stem 20, which is carried by the yoke I0. An appropriate operating member for the threaded stem may be provided in the form ,of a hand wheel, shown at 2 I.

It is clearly evident that when the strut assembly I9 is maintained in effective position it applies pressure directly on the closure member I4, which opposes the water pressure in the pipe line and serves to maintain the closure I4 in sealing position. However, when the strut assembly I9 collapses the closure at provide a steady stream of water;

The strut assembly I9 is shown as comprising a bridge 22,that is formed with a recess which receives a point 23 formed on the stem 20. At one end the bridge 22 is provided with a transverse notch 24 and adjacent to the other end with a 7 depression 25. A strut member 26 has a knife A fusible disc which normally I4 is free to blow off and 7 edge at each end. One of these knife edges is received in the notch 24 and the other in the notch I8.

At the lower end the strut 26 is provided with an outwardly extending tab or projection 21, which is provided with a recess 28. A cylinder and piston assembly, to be hereinafter described in detail is interposed between the bridge 28 and projection 21, to maintain the strut assembly in closure supporting position.

A cylinder 29 is illustrated as being made from a transparent material, such as quartz, and is formed at its upper end with a projection or boss 9 that is received in the recess 25.

A piston'3ll is disposed within the cylinder 29, and this piston is of an appropriate noncorrosive metal, such as Monel metal. The piston, at its lower end, is formed with a. projection or boss 8 which is received in the recess 28, and a fusible disc, indicated at 3I, normally maintains the piston 30 and cylinder 29 in an extended relationship. This disc 3| is made from a fusible material, such as a metallic alloy which is well known in this art, and which will fuse at a certain predetermined temperature which preferably will be indicated by indicia on the disc 3I, which preferably may take the form of a coloring thereof.

With the sprinkler in position on the extremity of the pipe line, the closure I4 is normally maintained in sealing position by the strut assembly I9. At any time prior to or subsequent to installation of the sprinkler, anyone-may readily ascertain that the sprinkler includes the proper fusible disc due to the transparent cylinder 29 and the coloring of the disc.

When the temperature-at which the disc 3I will fuse is reached, the fusion takes place, causing a collapse of the cylinder and piston assembly 29 and 30. 'I'he'bosses 9 and 8 fall out of the recesses 25 and 28, permitting the bridge 22 to fall downwardly and cause a general folding up and collapse of the strut assembly I9.

The frame 22 is now free to fall away, leaving the closure I4 entirely unsupported, whereupon the effect of water pressure in the pipe line will blow the closure out and start the stream of water for fire fighting purposes, as intended.

It is notable that the fusible disc 3I is effectively housed by the cylinder 29 to properly protect the same from atmosphere and other detericrating or disintegrating causes. cylinder disposed above the piston, the accumulation of any foreign matter between the bore of the piston and cylinder is prevented. If the sprinkler should be installed in an inverted position, the cylinder 29 and piston 30 may be interchanged to maintain the relationship of having the cylinder above the piston.

While a preferred specific embodiment of the invention ishereinbefore set forth, it is to be- Also, with the said fusible disc including indicia for indicating the temperature at which the disc fuses.

2. A collapsible element for use in the collapsible strut assembly of an automatic sprinkler, said element comprising a cylinder and piston arrangement for maintaining the strut assembly in a non-collapsed position, said cylinder and piston being collapsible to cause collapse of the strut assembly, said cylinder being of transparent quartz, and a fusible disc in said cylinder against which the piston engages, said fusible disc being provided with indicia for indicating the temperature at which the disc fuses.

3. A collapsible element for use in the collapsible strut assembly of an automatic sprinkler, said element comprising a piston, a cylinder disposed above said piston, said cylinder being of transparent quartz, and a fusible disc, colored to indicate the temperature at which it fuses, disposed above said piston and within said cylinder.

4. A collapsible element for use in the collapsible strut assembly of an automatic sprinkler, said element comprising a piston of Monel metal, a fusible disc in engagement with said piston and colored to indicate the temperature at which the said disc fuses, and a transparent quartz cylinder disposed about and above said piston and housing the fusible disc. 

